Damping system for musical instruments.



M. L. SEVERY & G. B. SINCLAIR.

DAMPING SYSTEM FOR MUSICAL INSTRUMENTS.

APPLICATION FILED DEC. 6. 1909.

Patented May 16, 1916.

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M. L. SEVERY & G. B. SINCLAIR.

DAMPING SYSTEM FOR MUSICAL INSTRUMENTS.

: APPLICATION FILED DEC. 6, 1909- I 1,183,245 atented May16, 1916.

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UNITED ST les arnn'r FFICE.

MELVIN L. SEVERY, OF ARLINGTON HEIGHTS, MASSACHUSETTS, AND GEORGE B.

- SINCLAIR, 0F GEORGETOWN, MAINE. A

SSIGNORS TO CHOBALCELO COMPANY, 015

BOSTON, MASSACHUSETTS, A conronarron or MAINE.

DAMPING SYSTEM FOR MUSICAL INSTRUMENTS.

Specification of Letters Patent.

Patented May 16, 1916.

To all whom it may concern:

Be it known that we, MELVIN L. SEvERY, of Arlington Heights, in the countv of Middlesex and Commonwealth of Massachusetts, and GEORGE E. SINCLAIR, formerly of .Medford, in said county and Commonwealth, but now of Georgetown, in the county of Sagadahoc and State of Maine, both citizens of the United States, have invented certainnew and useful Improvements in Damping Systems for Musical Instruments, of whichthe following is a specification.

' This invention relates to that class of musical instruments wherein tuned sonorous bodies are vibrated by electro-magnets having suitably timed electric pulsations delivered thereto; and our improvements pertain to means controlling both the mechanical and electrical vibration of said sonorous bodies, such means comprising both the initiating and terminating of the vibrations of said bodies.

One of the oh'ects of the invention is the construction of electrically controlled means whereby a single elongated damper, normally resting against a group ofstrings, can be withdrawn therefrom whenever the operator depresses one or more of the keys which actuate said strings. Such a damper we term a blanket damper, and design the same for a group of notes at some designated part of the instrument, as for one or more octaves of the bass notes.

A further object of the invention is to provide individual damping means which may be employed simultaneously with the blanket damper, wherever the latter is used, or which may be controlled electrically and mechanically when used alone.

In certain co-pending applications we have shown. described and claimed, features which are illustrated and described in the present application, but which are not herein claimed, and in other co-pending applications we have broadly claimed the art of producing musical tones, which art is involved but not claimed in the present application. All matters set forth and claimed in co-pending applications filed in ournames, min the name of either of us, and not specifically claimed herein, are expressly reserved for one or another of such applicaapplications Serial No. 273,199, filed August 7, 1905; Serial No. 379,714, filed'June 19, 19.07; Serial No. 384,872, filed July 22, 1907; Serial No. 537,257, filed January '10, 1910; Serial No. 573,135, filed July 21, 1910; Serial No. 745,400, filed J an. 31, 1913; Serial No. 753,013, filed March 8, 1913; Serial No. 753,014, filed March 8, 1913; and Ser. No. 757,872, filed Mar. 31, 1913;

Referring to the drawings forming part of this specification, Figure 1 is a vertical section, on the dotted line X.X in Fig. 2, of our blanket damper, showing also a side sectional elevation of the keyboard of the instrument, and the electrical connections between such parts. Fig. 2 is a front elevation of the blanket damper. Fig. 3 is a plan view of a portion of a key-board. and of the key-controlled switch. Fig. 4 is a sectionon XX in Fig. 2 showing a slightly modified form of the invention.

in said drawings, the reference numeral 1 designates the strings of the instrument to the arms 5 whose opposite ends project from the bar 0 hinged to the rail 7; the fastening means consisting of leaf springs 9 screwed to each, as shown in Fig. 1. The rail 7 is supported by said ribs 2; and a torsion spring 8 (Fig. 2) acts upon the frame comprising said parts 3, 5 and 6, to resiliently press the damper away from the strings. We prefer to thus have the blanket damper yieldingly pressed-away from the strings, and to hold it in its damping position by electromagnetic means, for two or three reasons. One is that in case the instrument is not being operated electrically, the blanket damper will leave the strings free for percussive actuation.

To electrically operat' theblanket damper,

' tions. Among these may be noted our joint we provide a horse-shoe magnet 10 between projecting from the rail 13; the latter being fastened to said ribs 2. From this armature eXtends a slender, longitudinally adjustable link let to the knee 15 held by the bar 6 and cross-bar 16. When said magnet is energized, said armature turns to present its ends more directly to the poles of the magnet, and thereby draws upon said link and swings the damper into contact with the strings. So long as current is supplied to said magnet, the damper remains in engagement with the strings. To release the same whenever any one or more-of the keys 20 are depressed, we provide a switch controlled thereby for breaking the circuit to said electromagnet 10.' Such switch comprises a frame consisting of the two hinged arms 21 located beneath said keys, and a rod 22 carried by said arms close under all the keys which control the strings in the field of the blanket damper; a spring or springs 23 yieldingly supporting said arms and rod in such position, and contacts 2 1, 25, as shown in Figs. 1 and 3. Between said contacts, electromagnet 10 and a current-source 27, are suitable connections 26,

28, 28 and 29; the connections 28, 28" being provided with a hand-controlled switch 30 for enabling the player to throw the blanket damper out of commission at will. The switch controlled by said arms and rod may be a small mercury cup 25 entered by a pencil 2 4, as shown in Figs. 1 and 1, or' it may be a connection of the type shown in Fig. 3.

Among other advantages of our blanket damper are these: The usual, or individual, dampers are incapable of efiiciently damping the more powerful bass strings, when played at their loudest, and the vibrations thereof consequently run into each other. Our blanket damper, onthe other hand, being controlled by'the pressure of the keys, but not deriving its power therefrom, can

be made to press and damp the strings'asheavily as required without affecting the touch of the keys. By having a constantly acting spring for withdrawing the damper,

and electromagnetic devices for its return controlled by the position of any one or more of the selected keys, it makes no difference how lightly the keys are played, the blanket damper leaves the strings and then returns thereto with all the pressure requisite. Vs-provide a switch 30 conveniently located as indicated in Fig. 1, for permitting the player to instantly throw the blanket damper into and out of commission. When rendering pianissimo passages, he will prefer to turn said switch so that the damper will be out of use, but for the heavier 'fparts the switch will be closed again, and

the damper permitted to act. I

The construction illustrated by F ig. 4 differs from that shown in Fig. 1 by having a spring for pressing its damper 3 against the strings, and electromagnetic means for removing it therefrom. For enabling the armature 11 to withdraw the damper from the strings, the link 14 from said armature is connected with a bell-crank lever 33 whose other end acts through a rod 34: against the damper frame. The pencil 21 is here carried directly by the frame 21, 22' and normally out of contact with the mercury in the 01113 25. Hence, the spring 8 normally acts to keep the damper against the strings; but upon the depression of one or more keys 20, said pencil enters the mercury, the circuit is closed, the electromagnet 10 energized, and the damper drawn away from its strings. In Fig. 1, the said pencil 24 is carried by an intermediately fulcrumed lever 32, the opposite end of which is joined to the frame 21, 22; and consequently when the frame is 35 depressed by the action of any of the keys 20 said pencil is withdrawn from the mercury in the cup 25, the circuit broken, the elec tromagnet 10 demagnetized, and the spring 8 permittedto throw the damper away from the strings. Not only does the cup 25 contain mercury 25 but in addition thereto a more or less thick film of oil 25 lying upon the surface of the mercury. This film of oil prevents the oxidation and dissipation of 5 the mercury, and at the same time reduces the ill effects resulting from sparking. The special advantages of this construction for damping purposes are that the noise of a metallic switch is eliminated, and that a 00 more perfect connection is thereby formed without putting an excessive load upon the keys controlling the switch.

We do not confine ourselves to a spring and an electromagnetic device for operating our blanket damper, inasmuch as it may easily be controlled in other ways; for example, the electric devices of Fig. .1 and of F ig.'1 may both be used and be made to act upon a single blanket damper, thus moving it electrically in both directions.

While this blanket damper-i may be employed with any usual type of musical instrument employing vibrated sonorous bodies, it is preferably auxiliary to our electrically actuated musical instruments above referred to, and to our electrical individual damper lifts. This is illustrated in Fig. 1, each string 1 being shown as provided with its individual damper 35 withdrawn in the ordinary manner by the key-action. In addition to, or in place of such mechanical lifting, we provide each with an electromagnet 37 adaptedwhen energized to perform such function. Our preferred means for ening from the latter into engagement with 139 the tail 36 of a damper 35. When said electromagnets are energized, their respective armatures are forced downward, the spoons thrown forward, and the dampers lifted from their strings. For energizing said electromagnets 37, upon the depression of the keys 20, the following system of wiring is arranged: From the motor-generator, or other current-source 45, a wire 46 is run to the brushes 47 controlled by said keys. A wire 48 from a contact 49 of each said brush goes to its proper electromagnet 37, and from the latter pass wires 56 and-56 common to all the magnets-37 back to the source 45. Now, whenever a key 20 is depressed and its brush 47 rises into touch with its contact 49, current will pass to its associated electromagnet 37 and lift its damper from engagement with a string 1. Simultaneously therewith, current flows from said source, through the wire 46, brush 47, contact 49; and wire 50 to the associated electromagnet '51, and back through a suitable wire 52, the harmonic controller 53, pedal switch 54 to the pulsation devices 55,

and thence through the wire 56 to said source 45. Hence whenever a string is vibrated by its energized electromagnet 51, current is simultaneously switched to the e-lectromagnet' 37 which controls its damper, and the latter instantly lifted from'such string. It consequently makes no difference whether a string-vibrating electromagnet is energized by pulsations normal to such string, or whether other pulsations are switched thereto. from the pulsation device by the harmonic c0ntroller,in every case the proper damper is instantly lifted from its string. Furthermore, the action of the dampers is not affected by the amount of current traversing said string magnet. i

In our drawings we have, for the sake of simplicity, shown but a single blanket-damper acting upon a single group of notes, but we do'not confine ourselves to this construction. In practice, we often prefer to use a plurality of blanket-dampers, thus decreasing the size of the group controlled by each and the mass to be moved. By following this plan and increasing the number of contact-controlling rockers or frames 21, 22, these too can be made lighter and the work of their actuating keys correspondingly decreased.

All that prevents us from providing each string with two dampers individual thereto is the expense and complication of the same, it being a great deal cheaper and simpler to provide a single damper for a. large number of the strings, in addition to the necessary one set of individual dampers. On the other hand, to make a blanket damper large enough to control a considerable number of strings, will be objectionable because of the heavy blow when the same acts; because of the heavier action or resist ance thereby given to the keys, and the less ened freedom and independence in expres sion, since all the strings which are under the influence of the blanket damper, being circumstanced alike, cannot be separately damped by the player. We have found the preferable arrangement to comprise one or two blanket dampers each of which embraces about one octave of strings, this giving the maximum of freedom with the minimum of complication and expense in construction.

The term group as herein applied to strings, notes, sonorous bodies and the like, refers only to a plurality of bodies having different pitches, and does not refer to that plurality of sonorous bodies tuned to the same pitch, commonly called unisons.

The function of the keys of a musical in strument, of the class described herein, be ing that of controlling an action, we wish to be understood when we use the term key in the claims, to include any means for controlling the action, since it is obvious that our invention could readily be adapted to self-players and the like whether or not of the type acting directly upon the keys of the instrument.

By our method of damping the sonorous bodies simultaneously in more than one point, we secure a perfection of damping far greater than is otherwise possible.

Nhat we claim as our invention and for which we desire Letters Patent is as follows, to wit 1. lhe combination with sonorous bodies tuned to different notes of the musical scale and means for their vibration, of a single extended damper coacting with several of said bodies and adapted to damp them all simultaneously, and means controlled by a part of the first-named means for applying said damper to said bodies and withdrawing it therefrom.

2. In combination with sonorous bodies tuned to different notes of the musical scale, and with means for effecting their vibration; an extended damper common to a plurality of said bodies and adapted to damp them simultaneously; and electric means for applying said damper, said means being controllable by the several means through which vibration of the bodies subject to said damper is effected, whereby said damper will be applied to the several bodies under its control when the vibration-effecting means of any one of such bodies is brought into action.

3. The combination with sonorousbodies tuned to difi'erent notes of the musical scale and means-for their vibration. of a singleeXtended dampercoacting with sex'eral of said bodies and adapted to damp them all simultaneously, and electric means controlled by a part of the first-named means for controlling said damper.

4. The combination with sonorous bodies tuned to different notes of the musical scale and means for their vibration, of a single extended damper coacting with several of said bodies, and means controlled by a part of the first-named means for causing said damper automatically to release all its associated sonorous bodies upon the vibration of each of them.

5. The combination with sonorous bodies tuned to different notes of the musical scale,

means for their vibration, and keys controlling said means, of a single extended damper coactingwith several of said bodies, and

means controlled by each of said keys for operatively moving said damper.

6. The combination with sonorous bodies tuned to different notes of the musical scale, means for their vibration, and keys controlling said means, of asingle extended damper, and electromagnetic means controlled by each of said keys for moving said damper in one direction.

7. The combination with tuned sonorous bodies embracing a plurality of octaves,

means for their vibration and keys controlling said means, of an extended blanket damper adapted to quench the vibration of a multiplicity of juxtaposed sonorous bodies, resilient means pressing said damper in one direction, electro-magnetic means for pressing said damper in the,opposite direction, one of said directions being such as will put said damper into engagement with said mule tiplicity of bodies, and keyrcontrolled means for energizing said electromagnetic means.

8. The combination with sonorous bodies, means for their vibration, and keys controlling said means, of a single extended damper coacting with several of said bodies, electromagnetic means normally holding said damper in engagement with said bodies, resilient means for pressing said damper out of such engagement but normally overcome by said electromagnetic means, and key-controlled means for energizing said electromagnetic means.

9. The combination with sonorous bodies,

means for their vibration, and keys controlto each of said bodies, an extended blanket damper disposed to quench the vibrations of a multiplicity of said bodies, and means controlled by a part ofthe first-named means for actuating both kinds of said dampers simultaneously.

11. The combination of sonorous bodies tuned to the notes of the musical scale; means for effecting their vibration; and a plurality of dampers for said sonorous bodies, positioned to act upon such bodies at Widely separated points but at the same side thereof, the dampers of each such body being under the control of and operable simultaneously with the means through which such body is brought into vibration.

12. In combination with sonorous bodies tuned to the notes of the musical scale, means for bringing said bodies into vibration; av plurality of dampers for said bodies, certain of said dampers being individual to the several bodies and another being common to a plurality of said bodies, the dampers common to any given body of the series being simultaneously controllable by the means which brings said body into vibration. a

13. A musical instrument comprising, in combination, sonorous bodies tuned t the notes of the musical scale; means for effecting their vibration; dampers individual to the several bodies; electromagnetic means for withdrawing said dampers; a blanket damper common to a plurality of said sonorous bodies; electromagnetic means for applying said blanket damper; and means for withdrawing and withholding the blanket damper from damping contact during such times as the electric blanketdamper-applyin means is inactive.

14. A musica instrument comprising, in combination, sonorous bodies tuned to the notes of the musical scale; means for effecting their vibration; dampers individual to the several sonorous bodies; electromagnetic means for withdrawing said *dampers; a blanket damper common to a plurality of said sonorous bodies; electromagnetic means for applying said blanket-damper simultaneously with the application of any of said individual dampers; and means under the control of the operator for rendering inoperative the electromagnetic means for applying the blanket damper.

15. The combination in a musical instrument, of a plurality of sonorous bodies; electromagnets intermittently attracting the same; a source of current and branch circuits connected with said electromagnets; dampers for said sonorous bodies; electromagnets controlling said dampers; a second circuit including the damper-controlling magnets and said source of current; and keys for respectively 'opening or closing simultaneously the circuits of the vibrationeffecting magnets and of the damper-controlling magnets of the respective sonorous bodies.

16. The combination with sonorous bodies, of means for their vibration, keys controlling said means, a blanket damper for a group of said bodies, means yieldingly pressing said damper away from said bodies, an electromagnet normally overcoming said yielding means and pressing said damper against said group, a source of current and a circuit therefrom to said electromagnet, a rod transversely located beneath the keys connected with said group, resilient means normally pressing said rod upward toward said keys, and a circuit closing de vice which through depression of a key and said rod breaks said circuit.

17. The combination with sonorousbodies, means for their vibration, and keys controlling said means, of a blanket damper for a group of said bodies, electromagnetic means for operating said damper, a source of current and a circuit therefrom to said electromagnetic means, a circuit closer in said circuit, an elongated inflexible body transversely located beneath the keys connected with said group, and adapted when depressed to actuate said circuit closer, yielding means normally holding said inflexible body up against said keys.

18. In combination with a sonorous body, an electromagnet for effecting its vibration; a damper for said body; an electromagnet for retracting said damper; a source of elec: tric current; a branch circuit including said source, the vibration-efiecting'magnet, and a pulsation-producing device; and a second branch circuit, including said source, the damper-retracting magnet, and means for opening and closing the circuit of said damper-retracting magnet.

19. In combination with a sonorous body, an electromagnet for effecting its vibration; a damper for said body; an electromagnet for retracting said damper; a source of electric current; a branch circuit including said source, the vibration-effecting magnet,

and a pulsation-producing device; a second branch circuit including said source, and the damper-retracting magnet; means for opening and closing said circuits re spectively; and a'key common to the circuitclosing devices of both branch circuits and serving when moved, to close both branch circuits.

20. In combination with a sonorous body,

electromagnetic means for vibrating said body, comprising a source of electric current, means for producing pulsations in said current, and an electromagnet; a pianoforte action for percussively vibrating said sonorous body; a damper; an electromagnet controlling said damper; an independent circuit for the damper-controlling magnet,

and

including the source of electric current and said magnet; and circuit-closing devices included in the respective circuits, and connectecb' with and operated by the pianoforte action; whereby the current delivered to the vibration-effecting magnet is rendered intermittent by the pulsation-producing device, while the current delivered to the damper-retracting magnet is unaffected thereby.

21. The combination of a sonorous body, an electromagnet for vibrating the same, a damper for said body, an electromagnet con trolling said damper, a source of current, circuits including said source and said electromagnets, the circuit including said first electromagnet having means for pulsating the current thereof, and a single means con trolling said circuits.

22. In combination with a sonorous body, an electromagnet for vibrating the same; a damper for said body; an electromagnet for actuating said damper; a source of electric current; branch circuits connecting said magnets and said source of current; a pulsation-producing device interposed between and in circuit with the vibration-effecting magnet and the source of current; a circuit closer for opening and closing simultaneously the circuits of the vibration-effecting magnet and of the damper-actuating mag net; and a key controlling said circuit closer.

23. The combination of a sonorous body, an electromagnet for vibrating it, a damper for said body, an electromagnet controlling said damper, means for producing pulsatory and non-pulsatory currents of electricity, a circuit for conveying the pulsatory current to the first-named electromagnetand a circuit for conveying the non-pulsatory current to the last-named electromagnet, the two circuits having a section com mon to both, and switching means adapted to open and close said circuits in said common section,

24. A musical instrument comprising sonorous bodies, electromagnets for vibrating said bodies; means for delivering correctly timed electric pulsations to said electromagnets; dampers for said sonorous bodies, normally in damping relation thereto; electromagnets for withdrawing said dampers; and means for delivering a non-pulsatory current to the damper electromagnets.

25. A. musical instrument comprising sonorous bodies, electromagnets for vibrating said bodies; means for delivering timed electrical impulses to said electromagnets; dampers .for said sonorous bodies, normally in damping relation thereto; electromagnets for withdrawing said dampers; a source of electric energy; branch circuits for the vibration-producing magnets and for the damper-actuating magnets, respectively; a

key-board; and circuit closing devices actuated by the keys of said key-board, and serving upon depression of a key to close the circuit of the vibration-producing magnet and of the damper-actuating magnet associated With said key andwith the sonorous body controlled thereby.

26. A musical instrument comprising tuned sonorous bodies, electromagnetic means for vibrating said .bodies; dampers individual to the respective sonorous bodies; a blanket damper for simultaneously damping a plurality of saidbodies; and electromagnetic means for actuating said individual and blanket dampers.

In testimony that We claim the foregoing invention, We have hereunto set our hands this 30th day of November, 1909. I

MELVIN L. SEVERY. GEORGE -B. SINCLAIR.

Witnesses:

A. B. UPI-1AM, CHARLES GARRISON. 

